Polyalkylene glycol mercaptosuccinimides dispersants for lubricant fluids

ABSTRACT

A NEW CLASS OF COMPOUNDS AND A SERIES OF NOVEL LUBRICANT COMPOSITIONS ARE DISCLOSED. POLYALKYLENE GLYCOL MERCAPTOSUCCINIMIDES WHICH ARE USEFUL AS DISPERSANTS IN POLYALKYLENE GLYCOL LUBRICANT FLUIDS AS SLUDGE DISPERSANTS AND LUBRICANT FLUID COMPOSITIONS INCLUDING SUCH MERCAPTOSUCCINIMIDES ARE DESCRIBED.

3,598,735 Patented AugQIO, 1971 3,598,735 POLYALKYLENE GLYCOL MERCAPTOSUCCIN IMIDES DISPERSANTS FOR LUBRICANT FLUIDS Ting-I Wang, Fullerton, Calif., assignor to Atlantic Richfield Company, Philadelphia, Pa. No Drawing. Filed Oct. 8, 1968, Ser. No. 765,994 Int. Cl. Clm 1/38 US. Cl. 252-47.5 1 Claim ABSTRACT OF THE DISCLOSURE A new class of compounds and a seriesof novel lubricant compositions are disclosed. Polyalkylene glycol mercaptosuccinimides which are useful as dispersants in polyalkylene glycol lubricant fluids as sludge dispersants and lubricant fluid compositions including such niercaptosuccinirnides are described.

BACKGROUND OF THE INVENTION Field of the invention 'This invention relatesv to chemical compositions and, more particularly, to chemical compositions useful as lubricating fluid additives and to lubricating fluid compositions. Still more particularly, this invention relates to polyalkylene glycol mercaptosuccinimide lubricant additives and lubricant compounds.

DESCRIPTION OF THE PRIOR ART Motor fuel lubricants, such as conventional automobile motor oil or oils designed for special applications, e.g., marine, aircraft and stationary engines, conventionally include oxidation inhibitors and dispersant additives. Viscosity improvers, etc. are also conventionally added to the basic lubricant fluid to provide particular characteristics desired in the end lubricating compound.

Large classes of hydrocarbon-based or hydrocarboncontaining additives are commercially available for use in Similarly, a principal object of the invention is to provide improved synthetic lubricant fluids for use as crankcase oils and as lubricants generally, which comprise polypropylene glycol diether as a base fluid and, an improved sludge dispersant additive.

A more specific object of the invention is to provide an improved dispersant additive comprising polyalkylene glycol mercaptosuccinimides. I

An additional and more specific object of the invention is to provide a lubricating composition including a polyalkylene glycol diether lubricant base fluid in combina- I tion with a sludge dispersant additive comprising polyalkylene glycol mercaptosuccinimides.

A further and more specific object of the invention is to provide a class of polyalkylene glycol mercaptosuccinimides for use as lubricant additives.

A, process for preparing lubricant additives and lubricant fluids constitutes an additional and still more specific object of the invention.

The provision of the specificcompounds described hereinafter and the specific processes for producing these compounds and the described lubricant fluids constitutes an additional and highly specific, but non-limiting, object of the invention. I

DESCRIPTION OF THE PREFERRED EMBODIMENT,

The foregoing and additional objects are accomplished in general by preparing the desired polyalkylene glycol mcrcaptosuccinimide and blending the resultant product with a propylene glycol diether polymer lubricating fluid generally of the type identified as Ucon fluid DLB-200E or equivalent.

The dispersant additivesof this invention are prepared, in general, by refluxing mercaptosuccinic acid or mercaptosuccinic anhydride with a polyalkylene glycol, then refluxing the product of the foregoingreaction with an amine, preferably a polyalkylene polyamine, at a temperature sufficiently high to initiate the reaction and remove water. A solvent, such as toluene, xylene, etc., may be used during the refluxing operations, if desired.

The first step of the reaction, the formation of the polyalkylene glycol derivative of mercaptosuccinie acid is carried out under atmospheric pressure, with or without the addition of solvent, at a temperature of from about 50 C. to about 250 C., and preferably in the range of about 80 C. to 250 C. for from about 1 to about 500 hours, preferably from about 10 to about 150 hours.

The second step of the reaction, the formation of the succinimide by reaction of the polyalkylene glycol derivative of mercaptosuccinic acidwith a polyalkylene polyprovide improved dispersant additives for non-hydrocarbon lubricant fluids.

SUMMARY OF THE INVENTION A new class of synthetic crankcase oils for use in automobile engines, aircraft engines, marine engines, stationary engines and the like, are described. The basic fluid, in the preferred embodiment, is a polypropylene glycol diether polymer identified .hereinafter as Ucon fluid DLB-200E. It has been found that while many oxi-.

amine is also preferably carried out at atmospheric pressure preferably in the presence of a solvent which is inert to the reaction, such as paraflinic and cycloparaflinic hydrocarbons, benzene, alkyl-benzenes, etc., e.g., toluene and xylene. The reaction may be carried out from about 50 C. to about 300 C., preferably in the range of from about C. to 150 C. for reaction times of between about one-half hour and 40 hours, preferably from 1 hour to 8 hours; I

The process is illustrated by the following specific embodimcnt showing the reaction conditions thereof.

0.l mole of n polypropylene glycol ether identified as Ucon fluid Lit-385 (0.1 mole) and mercuptosuccinic'ucid (0.1 mole) were added to n 500 ml. rcuctlon'flnsk. Ucon Saybolt seconds at 210 F. of 75, at F. of 385 and at 0 F. of 15,000, a viscosity in centistokes at 210 F. of

l4.3, at 100 F. of 83.3, and at 0 F. of 4,700 with a pout point (ASTM D-97) of F. and a fire point crease to about 200 C. as benzene was partially removed In (ca. ml.). At this point, the reaction vessel was cooled down to 45 C. and reheated to C. The temperature increasedto 96' C. and the reaction was allowed to continue for a total running time of 136 hours.

Tetraethylenepentamine (0.04 mole) and mls. of toluene was added and the reaction mixture was refluxed at C. for 6 hours. Moisture coming off from the reaction mixture was collected as the color of the reaction mixture turned to a dark brown. After 6 hours, the reaction was stopped. A sample of the product was vacuum treated at C. and 15 mm. Hgtoremove the solvent,

toluene, prior to solubility testing and evaluation for dispersant efl'ectiveness. 3

The product of the above reaction was blended with an end-blocked polypropylene glycol ether identified as Ucon I fluid DLB-ZOOE at a 5 percent concentration level. The

. composition was clear with no observable cloudiness or separation. An oxidation inhibitor Oronite 254 was added at a 3 percent level.

Dispersant effectiveness was tested by blending the additive to used Ucon DLB-200E obtained from engines used in dynamometer tests. The dispersant additive product of the aforementioned process was mixed with the ma! terial to be tested in a Waring Blendor for 5 minutes; The sample was observed for sludge separation'and paper chromatographic spot tests were made to determine dispersant effectiveness. Data showing the relative effectiveness of the composition of this invention are given in Table I along with comparative data using other known and experimental dispersant additives.

TABLE r.nrsrnasxr-z'r 'rnsrs [Waring Blendor. high speed-6 minutes] Hours Settling Percent conton- Percent Code Number trntion Structure separation Standard Il... 100 Used Ucon irom chassis dynamometer test on Chavrolet 19 72 Standard '2 100 Used Ucon irom chassis dynnmomctcr test on Ford 4 68 64942-2... 5 Mercaptosucciuic ncid plus Ucon LB-385 plustetraethylenepentamine r 3 CHI R- OCHz il s-C1100 N.CH1CH;NH--H /a ,H CO

and/or l H8-CflC0:--CHCH:0R

HiCO(NHCH;CH|- NH:

4 m-at-o s on; on. 4" 4;; ouna-cncorcnclr otm'cn on v I 11:00:11 640-364 s Totrapropenylsuccinic anhydride plus tricthylenotctrnminc.. 3 119 mat-7 5 cu. I cm 3-72 s .C|slIn-CIlC0|tJHCHz-\O(EHCH OR I HaCO-NHCH:CH NH:

0412-21-1 a, CnIln-CIIGO 17 an NCHaCHzCHzNHCHaCHzCHsNHI 640-14-1 6 CnHn-CHCO 6-72 16 Nomcnmncmcnmm HICO Plus Ctallu-CllCO v/Ct)-Cil:

NCHaCUaNHCHzCHzN B100 (30- H-CnHfl 64949-1 l5 Calla-CHICO 3 58 NCHrCHzNH:

CHzCO 1 Soap like deposits formed on graduate.

- .Ucon fluid nus-200E available from Union Carbide The significant advantages of the compositions of this invention compared with other dispersant compounds are immediately apparent. The significantly greater effective ness as a dispersant additive of the inventive compounds,

CH: ns-oncoui a- -ocri,cn-on (CH: ns-cHco.--bncn.0 n 5,0 l.

o ,oo :1

and

on. mN- cmcmmr -n ns-cncor -encmo -a on, ns-cHco,-(':Hcn,0 R 11.0

, n,co(NHcrI,crr, Ntr,

on, ns-cacoar noctr,i;n-on a mconr v CH:

. RTOClDH s-cucom 11,0

and

\ l- V I... moo,

CH: n-vmmim s-cnco JJIBCO wherein n and m are positive integers. In the foregoing process, a polyalkylene glycol wherein n was 25 and a polyalkylene amine wherein m was 4 were used; however, n may be a positive integer from 1 to 100 and m may be a positive integer from 1 to 10. Normally, I: should be greater than and, within broad ranges, It should be at least about 3 times m and preferably from 5 to times m. R is a lower alkyl group or hydrogen, preferably methyl.

In addition to being effective as adispersant additive for lubricants, the compounds of this invention, by reason of the mercapto structure, also serve as anti-wear agents and are effective as corrosion and oxidation inhibitors, thereby reducing the required concentiation'of specially compounded corrosion and oxidation inhibitors.

The lubricating compositions of this invention are preferably formed by blending the mercaptosuccinimide compounds heretofore described with end-blocked polyalkylene glycol ether lubricating fluids, for example the end-blocked polypropylene glycol ether identified as of the present ene glycol ether lubricating base fluid, a mercapto r ing additives.

Plastics and Chemicals Department, New York. The dispersant additive concentration level is from 0.1 to 10 percent generally, preferably from about 1 percent to about 5 percent, by weight. Oxidation inhibitors are also added in the 0.1 percent to 5 percent range, preferably in the range of from 0.5 percent to 3 percent. Many conventional oxidation inhibitors were tested and found to be successful, for example, 3 percent Oronite 254 is the preferred additive but 1 percent concentration of 4,4- methylene, bis-2,6ditertiary butyl phenol (Ethyl702), an alkylated phenol (Lubrizol 814), phenyl alphanaphthylamine, and Lube SL) were found to be successful oxidation inhibit- Ucon DLB-200 fluid is amber in color, has a viscosity at 210 F. of 58.3 (SUS), at 100 F. of 201 (SUS) and at 0 F. of 5660 (SUS). The viscosity, in centistokes, is 9.70 at 210 F., 43.2 at 100 F., l230at 0 tF-, 4140 at 20 F. and 23,800 at 40 F. The viscosity index is 161, the pour point is F., the flash point is 520 F. and the fire point is 565 F. This product is described in Union Carbide Chemicals Company Advance Technical Information publication F-40400, June 1959. Double end-blocked lubricants of this class generally may be used in the compositions of this invention,-the' primary consideration being the desired viscosity and viscosity index. The manufactureand properties of these compounds is discussed by Gunderson and Millet, Synthetic Lubricants, Reinhold, New York, 1962, chapter 7 on -Polyglycols. Reference is made to this work and the publications and patents cited therein for a complete discussion of the lubricant base stocks used in the inventive composition.

It is difficult to overestimate the importance of providing the proper blend of lubricating fluid, dispersant additive, and oxidation inhibitor. To

invention, e.g., an end-blocked polyalkylsuecinimidedispersant additive of the type described, and

. ciples and teachings Oronite 254, there is pro- The lubricatan oxidation inhibitor, 'e.g., vided a potential lifetime motor lubricant. ing properties of normal operating conditions; however, over long periods of time the base fluidmay be oxidized to form volatile, components which are discharged from the crankcase.

An effective oxidation inhibitor is, therefore, necessary to prevent too rapid decomposition'of the base lubricating fluid resulting in-the necessity for continual addition of lubricant. Sludge'is formed in every internal combustion engine from combustion products, wear products, etc. It is essential that this sludge be maintained in the lubricant and carried to an effective filter. Therefore, an effective dispersant additive is required to provide an essentially homogeneous circulatinglubricant fluid in which the sludge forming materials are maintained in dispersion. As the homogeneous fluid is circulated through the oil filter, the sludge components are removed and the clean lubricating fluid is returned to the crankcase. Except for occasional addition of lubricating fluid, no additional attention need be given to a vehicle's engine lubricating system. The convenience and economy of this type of fluid are immediately apparent.

The lubricating compositions of this invention, the dis: persant additives, and the process for preparing these products have been set forth in rather specific terms to aid those skilled in the art to understand and to practice the invention. Departures from the specific disclosure will be made by those skilled in the art based upon the prinherein and such variations may be made without departing from the spirit and scope of the invention, as defined in the following claim.

I claim:

1. A lubricant compositioncomprising:

a minor portion of a polypropylene glycol diether and a minor portion, sufiicient to impart dispersant propan alkylated diphenylamine (Vanillustrate, using the fluids v the base fluid are not diminished under,

erties of a compound selected frbm the group consist- 5 and 15 time s-m, and R is a lower alkyl or hydrogen; ing of and mixtures thereof. 421 References cma 5 Y V UNITED STATES PATENTS 3,211,651 /1965 Elliott =1 21. 2s2 ,47.sx 3,299,121 1/1967 Vineya'rd 2s2-47.sx and r I 1 3,428,615 2/1969 Stuart et a1. 252-52 on. Y 10 DANIEL E WYMAN, Primary Examiner R- OCH*(EH-BCHCO W. H. CANNON, Assistant Examiner I N- cmcmNn -n 1 us. cl. X.R. H100 260-326, 561 1 V wherein n is a positive integer between 8 and and m is a positive integer between 1 and 10 and n is between 

